In the prior art, a backlight module has a structure as shown in FIG. 1. The backlight module comprises a light guide plate 01, a reflecting sheet 02, a light source 03, a light source reflective cover 04, a diffusion plate 05, a lower prism film 06 and an upper prism film 07. The light guide plate 01 is provided with lattice points 011 on a surface facing the reflecting sheet 02, and the reflecting sheet 02 is situated on a side of the light guide plate 01 facing away from the diffusion plate 05.
In an existing backlight module, the lattice points 011 on the surface of the light guide plate 01 facing the reflecting sheet 02 are positioned outside the light guide plate 01. After the backlight module is assembled, the lattice points 011 on the light guide plate 01 will be in direct contact with the reflecting sheet 02; as a result, the lattice points 011 on the light guide plate 01 and the reflecting sheet 02 will scratch each other in case of a relative movement due to vibrations during delivery or use of the backlight module, which results in a short life time of the backlight module and influences the luminance uniformity of the backlight module.